Academy of Science. 61 



The hottest mouth of the year was July, with mean temperature of 76''.G3; the 

 hottest week was June 19th to 25th, mean temperature 83°. 41; the hottest days were 

 June 22d and July 16, which each had a mean temperature of 86°. 6. The mercury 

 reached or exceeded 90° on 32 days, viz: 3 in May, 13 in June, 8 in July, 2 in 

 August, and 6 in September. There were 58 such days in 1874. The mercury did 

 not reach 100° during the year. 



The last light frost of spring was on May 4th; The first light frost of autumn was 

 on September 18th, giving a period of 137 days entirely without frost. The last 

 severe frost of spring was on April 17th; the first severe frost of autumn was on 

 October 30th, giving a period of 196 days without severe frost. No cold weather 

 during the year caused any damage to fruit. 



The entire amount of rain, including melted snow, was 28.87 inches, which is 

 precisely the same amount as in 1874, and falls below the average rainfall of the 

 past eight years by 4.11 inches. Either rain or snow fell on 106 days, 4 more than 

 the average number The longest interval without rain, during the growing sea- 

 son, March 1st to October 1st, was 18 days, June 8th to 27th. The number of 

 thunder showers was 21. 



SNOW. 



The entire depth of snow was 5 inches, which is the least annual amount on our 

 eight years' record, and is 20.36 inches below the average. Of this amount 4 inches 

 fell in February and 1 inch in March. There were flurries of snow in January, 

 April, November and December. The last snow flurry of spring was on April 

 12th; the first snow of autumn was on November 13th. 



PACE OF THE SKY. 



Average cloudiness of the year 44.81 per cent, of the sky, which is only .78 per 

 cent, below the average. The number of clear days (less than one-third cloudy) 

 was 162; half clear days (betwen one-third and two-thirds cloudy), 115; cloudy 

 (more than two-thirds), 88. There were 23 days without a cloud, and an equal 

 number without a trace of sky. June was the clearest month, with a mean cloudi- 

 ness of 31.44 per cent. January was the cloudiest month, mean cloudiness 54.84 

 per cent. The mean cloudiness at 7 a. m., was 47.67 per cent.; at 2 p. m., 48.32 

 per cent. ; at 9 p. m., 38.44 per cent. 



DIRECTION OP THE WIND. 



During the year (three observations daily) the wind was from the southwest 330 

 times; northwest, 298 times; southeast, 161 times; northeast, 135 times; south, 61 

 times; east, 47 times; north, 38 times; west, 10 times; calm, 15 times. The south 

 (including southeast, south and southwest) winds outnumbered the north (including 

 northeast, north and northwest) winds in the ratio of 552 to 471. 



VELOCITY OP THE WIND. 



The number of miles traveled by the wind during the year was 145,316. This 

 gives a mean daily velocity of 398.12 miles, and a mean hourly velocity of 16.59 

 miles. The position of the anemometer cups at an elevation of 105 feet above the top 

 of Mt. Oread, 325 feet above the river level, secures exposure to the full force of the 

 wind. The maximum velocity attained was 75 miles an hour, on January 8th. The 

 greatest daily velocity was 1,070 miles, on February 3d The strongest winds, were 

 in March and April;^the lightest were in July and August. 



